Logo appears much smaller under Layout Navigation Logo, than under Site Identity

And why does a 66x55 pixel logo appears just as large as a 500x500 pixel?

Hi there,

so the Site Header Logo you can control its size by adjusting the logo width in the customizer.

the navigation logo is sized by the Menu Item height in Customizer > Layout > Primary Navigation.
There is also some padding applied to the logo which does make it smaller that can be removed with CSS on your current setup:

.main-navigation .navigation-logo img {
    padding: 0px;
}

Thanks for the clarification David, it seems like the logo size stays the same, no matter what the upload size is, so how do I add a bigger logo?

So the site identity logo in the Customizer > Layout > Header --> Logo Width edit the field and delete the number so its empty. The logo will then be displayed at its original size.

The nav logo is as i mentioned above.

To be sure make the changes publish your settings and view the page in an incognito browser just to make sure the browser cache isn't interfering

So we are back with the issue I have with adding the logo under Site Identity, that the logo is not in line with the nav menu, but I guess it's a compromise.

If you can share a link to the site then we can advise on the best solution.

Thanks, I added the link. What I want is the logo to be about the size you see, but in line with the nav menu, not above or below, as the options are.

Meetup as inspiration

https://imgur.com/DHv3aaI

In Customizer > Layout > Primary Navigation you could set the Location to Float Right.